Upcoming Wet Season to Eliminate Current Drought in Hawai‘i

The existing drought conditions are expected to be eliminated by the end of the wet season, which runs from October 2019 through April of 2020.

That’s the conclusion reached in the annual Wet Season Outlook for Hawaiʻi issued by the National Oceanic and Atmospheric Administration’s Climate Prediction Center.

Forecasters say the current El Niño-Southern Oscillation-neutral conditions are likely to continue through spring 2020.  “In the last 30 years, eight out of the top 10 rainiest wet seasons have had El Niño-Southern Oscillation-neutral conditions,” according to the report.

The consensus of climate models favor above average rainfall through the wet season.  This projected pattern suggests a possibility of cutoff low-pressure systems that can produce intense rainfall, especially when combined with expected above average sea surface temperatures, according to NOAA experts.

For the dry season, which began in May and concluded in September 2019, many locations in Hawaii had above average rainfall.

NOAA states that the early start to the dry season, due to the effects of El Niño in early 2019 resulted in moderate to severe drought in all four counties in early May.

Drought conditions on Kauaʻi and Maui were lifted following an unusual June storm; but dry conditions in Maui County from July through September “brought the drought back quickly.”

Drought conditions on small portions of the Big Island and Maui reached extreme levels of D3 categories according to the US Drought Monitor map. This mainly affected ranching operations and contributed to an increase in brush fires, according to the report.

NOAA reports that Hawaiʻi had the seventh wettest dry season in the past 30 years in 2019.  Over that same three-decade period, 2015 marked the wettest dry season; and 2003 was the driest dry season.

NOAA Wet season preparedness reminders:

• Do not drive on roads with fast-flowing water: Just 2 feet of fast-flowing water can sweep most vehicles off a road.  Road may also be severely undercut.
• Do not walk across flooded streams: If you’re hiking and get stranded, wait for the water to recede. Streams in Hawaii generally recede quickly.
• Expect more rainy weather impacts: Increased road travel times; Possible detours or road closures due to flooding or landslides; and Outdoor activities may be postponed, canceled or adjusted.
• The wet season brings increased potential for lightning strikes: Be prepared for power outages; Move indoors when you hear thunder.
• Clear debris from gutters and drainage ditches to ensure water can flow freely.
• If you travel through a flood-prone area, identify alternate routes ahead of time.
• If you live in a flood-prone area, have an evacuation plan in case flood waters quickly threaten your home.
• Stay informed of conditions that could change rapidly: Sunny skies can turn cloudy with intense rainfall in less than an hour; Check out the latest forecasts, watches, warnings, and advisories via the media, NOAA Weather Radio, the Internet, or one of several weather mobile phone apps; Wireless Emergency Alerts (WEA) on mobile phones notify you that you’re in a flash flood warning area.

Online Resources:

• NOAA National Weather Service Honolulu HI
• NOAA Weather Ready Nation
• NOAA Climate Prediction Center
• FEMA Flood Preparedness Information
• Hawaii Emergency Management Agency
• State of Hawaii-DLNR National Flood Insurance Page
• US Drought Monitor